Global IDF definition

The metabolic syndrome, the clustering of visceral (abdominal) obesity, dyslipidaemia, hyperglycaemia and hypertension, is a major public health challenge worldwide as more and more people fall victim to the syndrome   1   2 . The syndrome is not benign as it is associated with a substantially elevated risk not only of type 2 diabetes (five-fold) but also of cardiovascular disease (CVD) (two- to three-fold)   1 . The metabolic syndrome is now thought to be a key driver of the modern day epidemics of diabetes and CVD   1 . Its increasing occurrence could possibly reverse the gains that have been made in many communities and nations through recent declining CVD morbidity and mortality.

The metabolic syndrome is not a new condition. Its description goes back at least 80 years being first described in the 1920s by Kylin   3 , a Swedish physician. This cluster of CVD risk factors has had a number of names including Deadly Quartet, Syndrome X, Syndrome X plus, and Insulin Resistance Syndrome   1  but metabolic syndrome is likely to remain the popular choice for the foreseeable future. Numerous definitions for the metabolic syndrome have surfaced and this has caused considerable confusion, just as has the variety of names used to describe the syndrome   4 .

The cause of the metabolic syndrome remains poorly understood, and likely to be complex and multifactorial   1 . Insulin resistance and abdominal obesity have received the most attention as the putative underlying features most likely to explain the frequently observed clustering of the other components. However, further research is required to determine which factors are central to the development of this syndrome. Several different factors are probably involved, many related to sedentary lifestyle but clearly, genetic factors also play a role.